[0001] The present invention relates to a liquid ejecting apparatus according to the preamble
of claim 1, and a control method thereof according to the preamble of claim 12. The
features of the preambles of claims 1 and 12, respectively, are known from e.g. document
US 2007/200885 A1 or document
US 2011/0228012 A1.
[0002] In a liquid ejection module such as an inkjet print head, evaporation of a volatile
component progresses in an ejection port in which no ejection operation is performed
for a while, which may lead to deterioration of ink (liquid). This is because the
evaporation of the volatile component increases the concentration of a component such
as a color material and, if the color material is pigment, causes coagulation or sedimentation
of the pigment, thereby affecting an ejection state. More specifically, the amount
and direction of ejection are varied and an image thus includes density unevenness
or a stripe.
[0003] In order to suppress such ink deterioration, a method of circulating ink in a liquid
ejection module and supplying flesh ink regularly to ejection ports has been recently
proposed. Document
WO 2016/068987 A1 discloses a method of providing a liquid delivery mechanism (pump element) in a circulation
flow path that supplies ink to each ejection port and controlling driving intervals
of ejection elements and the pump element.
[0004] The present invention in its first aspect provides a liquid ejecting apparatus as
specified in claims 1 to 11.
[0005] The present invention in its second aspect provides a control method as specified
in claim 12.
[0006] Further features of the present invention will become apparent from the following
description of exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007]
FIG. 1 is a perspective view of an inkjet print head;
FIGS. 2A and 2B are conceptual diagrams of ink circulation adoptable in the present
invention;
FIG. 3 is a block diagram illustrating a control configuration in a liquid ejecting
apparatus;
FIGS. 4A and 4B are diagrams showing a flow path configuration of a printing element
substrate in a first embodiment;
FIG. 5 shows an example of driving in the case of using a piezoelectric actuator as
a liquid delivery mechanism;
FIG. 6 is a diagram comparing ink evaporation rates from ejection ports;
FIG. 7 is a diagram showing a state where a plurality of liquid delivery mechanisms
are divided into blocks;
FIG. 8 is a timing chart of block driving;
FIGS. 9A and 9B are diagrams showing a difference in evaporation rate according to
the temperature and humidity of an environment;
FIG. 10 is a timing chart in the case of divisional driving;
FIG. 11 is a timing chart in the case of adjusting the number of times of driving
of the liquid delivery mechanism;
FIG. 12 is another timing chart in the case of adjusting the number of times of driving
of the liquid delivery mechanism;
FIGS. 13A and 13B are diagrams showing a flow path configuration of a printing element
substrate in a third embodiment;
FIG. 14 is a timing chart in the third embodiment;
FIG. 15 is another example of the timing chart in the third embodiment;
FIGS. 16A and 16B are diagrams showing a flow path configuration of a printing element
substrate in a fourth embodiment; and
FIG. 17 is a plan view of an alternating current electro-osmotic (ACEO) pump.
[0008] In document
WO 2016/068987 A1, although the optimization for each of circulation flow paths corresponding to respective
ejection ports is taken into account, consideration is not given to the entire circulation
flow path including a number of ejection ports. As a result, a problem described below
has occurred.
[0009] In a configuration having a number of ejection elements like a full line type inkjet
print head, an imbalance between ejection frequencies of ejection elements increases
variations in the degrees of ink evaporation and deterioration in a print head. On
the other hand, if ink is circulated sufficiently to avoid ink deterioration in all
ejection elements, a frequency of exposing liquid to the atmosphere through the ejection
ports becomes high, with the result that the amount of vaporization of circulating
ink as a whole is increased more than necessary.
[0010] Further, if a number of liquid delivery mechanisms are driven simultaneously, a large
current flows per unit time, which requires a large power supply capacity and leads
to an increase in cost. In addition, there is a possibility that a drive pulse to
be applied to the liquid delivery mechanisms affects a drive pulse to be applied to
the ejection elements and the effect of noise appears in ejection operation.
[0011] The present invention has been accomplished in order to solve the problem described
above. Accordingly, an object of the present invention is to provide a liquid ejecting
apparatus capable of circulating liquid suitably and maintaining stable ejection operation
while suppressing liquid vaporization, a power supply capacity, and the effect of
noise in a configuration of having a circulation flow path in correspondence with
ejection elements.
First Embodiment
[0012] FIG. 1 is a perspective view of an inkjet print head 100 (hereinafter also simply
referred to as a print head) that can be used in a liquid ejecting apparatus of the
present invention. The print head 100 has a plurality of printing element substrates
4 arrayed in a Y direction, each printing element substrate 4 having a plurality of
printing elements arrayed in the Y direction. FIG. 1 shows a full line type print
head 100 in which printing element substrates 4 are arrayed in the Y direction by
a distance corresponding to the width of an A4 size.
[0013] The printing element substrates 4 are connected to the same electric wiring board
102 through flexible wiring boards 101. The electric wiring board 102 is equipped
with power supply terminals 103 for accepting power and signal input terminals 104
for receiving ejection signals. An ink supply unit 105 has a circulation flow path
that supplies ink from an unshown ink tank to each printing element substrate 4 and
collects ink not consumed by printing.
[0014] With the configuration described above, each printing element provided on the printing
element substrate 4 uses power supplied from the power supply terminals 103 to eject
ink supplied from the ink supply unit 105 in a Z direction in the drawings based on
ejection signals input from the signal input terminals 104.
[0015] FIGS. 2A and 2B are conceptual diagrams of ink circulation adoptable in the present
embodiment. FIG. 2A shows a configuration in which ink is circulated between a supply
ink tank and the inkjet print head. Ink supplied from the supply ink tank to the print
head is partly consumed by ejection operation of the print head and ink not consumed
by the ejection operation is collected into the supply ink tank again. In a case where
the collected ink is deteriorated by evaporation of a volatile component in the print
head 100, the supply ink tank may have the function of adjusting components of the
collected ink.
[0016] FIG. 2B shows a configuration in which a supply ink tank and a collection ink tank
are separately provided. Ink supplied from the supply ink tank to the print head is
partly consumed by ejection operation of the print head and ink not consumed by the
ejection operation is collected into the collection ink tank. Providing a unit that
adjusts ink components of the ink collected into the collection ink tank makes it
possible to return the ink after adjustment to the supply ink tank. Both the configurations
may be applied to the liquid ejecting apparatus of the present embodiment.
[0017] FIG. 3 is a block diagram illustrating a control configuration in the liquid ejecting
apparatus. A controller 400 comprises a CPU 401, a ROM 402, and a RAM 403. The CPU
401 controls the entire apparatus based on programs and parameters stored in the ROM
402 by using the RAM 403 as a work area.
[0018] A head control unit 404 controls the inkjet print head 100. To be more specific,
the head control unit 404 drives a liquid delivery mechanism provided in the print
head 100 to circulate ink in the print head and drives an energy generating element
to perform ejection operation under instructions from the CPU 401. Specific control
performed by the head control unit 404 will be described later in detail.
[0019] A mechanism unit 406 includes, for example, a conveyance mechanism for conveying
a print medium and a maintenance mechanism for performing maintenance of the print
head 100. The mechanism unit 406 also includes a pump for circulating ink in the print
head 100, a negative pressure control unit for controlling a pressure (negative pressure)
in the flow path, and a valve for opening and closing the flow path. A mechanism control
unit 405 controls the whole mechanisms under instructions from the CPU 401.
[0020] A sensor unit 408 includes various sensors for confirming an environment where the
apparatus is placed and the states of the apparatus at different times, such as a
temperature sensor, a humidity sensor, and a sensor that detects a sheet feeding state.
The sensor unit 408 also includes a diode sensor for detecting a substrate temperature
of the print head 100 and a sensor for detecting a fluid pressure in ink circulating
in the print head 100. A sensor control unit 407 provides detection results obtained
from the sensors to the CPU 401. The CPU 401 drives the mechanism unit 406 and print
head 100 based on the information obtained from the sensors.
[0021] FIGS. 4A and 4B are diagrams showing a flow path configuration of the printing element
substrate 4. FIG. 4A is a perspective view of the printing element substrate 4 from
the side of ejection ports (+Z side) and FIG. 4B is a cross-sectional view. As shown
in FIG. 4A, a pressure difference produced by an unshown pump causes ink to flow through
the supply flow path 8 in a +Y direction. Ink flowing in the +Y direction partly flows
into individual flow paths 7 provided on both sides of the supply flow path 8 and
then returns to the supply flow path 8. Two pressure chambers 3 are provided in the
midstream of each individual flow path 7.
[0022] Two connection flow paths 6 and 6' connecting the two pressure chambers 3 to the
supply flow path 8 have different widths in the Y direction. A difference in flow
path resistance produces a unidirectional flow. In each individual flow path 7, the
connection flow path 6, which is located upstream and has a wide width, has a liquid
delivery mechanism 12 for accelerating a flow of liquid. With the configuration described
above, a flow is produced in each individual flow path 7 so that liquid flows from
the supply flow path 8 to the first pressure chamber 3 through the wide connection
flow path 6, flows into the second pressure chamber 3 through a communication flow
path 5, and returns to the supply flow path 8 through the narrow connection flow path
6'. The deterioration of ink near ejection ports 2 can be suppressed by controlling
the flow in each individual flow path 7 together with the flow in the +Y direction
in the supply flow path 8.
[0023] Although not shown in the drawing, it is preferable that a filter is provided in
the midstream of the connection flow path 6 to prevent foreign matter, bubbles and
the like from flowing therein. For example, a columnar structure can be used as the
filter.
[0024] FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. 4A. The printing
element substrate 4 is obtained by stacking a functional layer 9, a flow path forming
member 10, and an ejection port forming member 11 in this order on a substrate 4a
of silicon or the like. The supply flow path 8, individual flow path 7, and communication
flow path 5 are formed on the same plane by a flow path wall of the flow path forming
member 10.
[0025] Energy generating elements 1 are provided in positions corresponding to the pressure
chambers 3 on the functional layer 9. Ejection ports 2 are formed in positions corresponding
to the energy generating elements 1 in the ejection port forming member 11. Upon application
of a voltage pulse to the energy generating elements 1 based on an ejection signal,
film boiling occurs in ink contacting the energy generating elements 1 and the growth
energy of produced bubbles ejects ink as droplets from the ejection ports 2 in the
Z direction. In the present embodiment, a combination of the ejection port 2, the
energy generating element 1, and the pressure chamber 3 is referred to as a printing
element (ejection element).
[0026] In each individual flow path 7, the liquid delivery mechanism 12 is provided in a
position corresponding to the connection flow path 6, which is located upstream and
has a wide width, on the functional layer 9. The flow in the individual flow path
7 is accelerated by driving the liquid delivery mechanism 12 based on a drive signal.
[0027] Specific examples of the dimensions of the above structure are explained below. The
size of the energy generating element 1 is 25 µm × 30 µm, the diameter of the ejection
port 2 is 25 µm, and the area of the pressure chamber 3 is 30 µm × 35 µm. The upstream
connection flow path 6 has a width of 20 µm and a length of 40 µm, the downstream
connection flow path 6' has a width of 10 µm and a length of 40 µm, the communication
flow path 5 has a width of 20 µm and a length of 10 µm, and the whole of the individual
flow path 7 has a height of 20 µm. The width of the supply flow path 8 is 50 µm and
the thickness of the ejection port forming member 11 is 20 µm. The viscosity of ink
to be used is 2 cP and the amount of ink ejection from each ejection port is 10 pl.
[0028] In the printing element substrate 4 of the present embodiment, printing elements
are arrayed in the Y direction with a pitch of 600 dpi (dots per inch). Two printing
element arrays on respective sides of the supply flow path 8 are shifted from each
other in the Y direction by half the pitch. As a consequence, an image can be printed
at a resolution of 1200 dpi on a print medium that is conveyed in an X direction at
a predetermined speed.
[0029] Although FIG. 4A shows one supply flow path 8 and two printing element arrays located
on respective sides of the supply flow path 8, the printing element substrate of the
present embodiment further includes another printing element group shown in FIG. 4A
in the X direction to eject the same type of ink (see FIG. 7). That is, a pixel array
having one pixel width of 1200 dpi and extending in the X direction can be printed
by ejection operation using two printing elements alternately or in a predetermined
order. In a case where the liquid ejecting apparatus of the present embodiment is
a color inkjet printing apparatus, groups of four printing element arrays ejecting
the same type of ink are further arrayed in the X direction in a number corresponding
to the number of ink colors.
[0030] As the liquid delivery mechanism 12 of the present embodiment, an alternating current
electro-osmotic (ACEO) pump, an actuator or the like may be used. In the case of using
an actuator, various actuators such as a piezoelectric actuator, an electrostatic
actuator, and a mechanical/impact actuator may be used. In the description below,
a case of using a piezoelectric actuator as the liquid delivery mechanism 12 will
be taken as an example.
[0031] FIG. 5 shows an example of driving in the case of using a piezoelectric actuator
as the liquid delivery mechanism 12. The horizontal axis indicates time and the vertical
axis indicates displacement of the piezoelectric actuator. A voltage is applied to
the piezoelectric actuator, whereby the piezoelectric actuator protrudes in the flow
path and narrows the connection flow path 6. After the application of the voltage
is stopped, the piezoelectric actuator gradually moves down and restores the connection
flow path 6 to an original volume. In such a manner, the displacement of the actuator
asymmetric with respect to time and the difference in flow path resistance between
the connection flow paths 6 and 6' allow ink to flow through the individual flow path
7 in the direction shown in FIGS. 4A and 4B. In the present embodiment, one liquid
delivery operation is performed by applying a voltage three times in 100 µsec to displace
the actuator three times as shown in FIG. 5.
[0032] FIG. 6 is a diagram comparing ink evaporation rates from the ejection ports in the
case of circulating ink and in the case of not circulating ink. The horizontal axis
indicates time elapsed since the ejection ports were opened by removing a cap from
the print head 100. The vertical axis indicates an ink evaporation rate from the ejection
ports (the amount of evaporation per unit time and unit area).
[0033] In the case of not circulating ink, if a volatile component of ink is evaporated
from the ejection ports to some extent, concentration of ink staying near the ejection
ports progresses. The concentrated ink interferes with the evaporation of ink inside
the ejection ports, thereby gradually decreasing the evaporation rate of ink as a
whole. In contrast, in the case of circulating ink, a high ink evaporation rate is
maintained because flesh ink is regularly supplied to the ejection ports 2 and the
pressure chambers 3. More specifically, the evaporation rate is stabilized at a value
at which an evaporation rate from the ejection ports 2 is in proportion to a rate
of replacement of ink with fresh ink corresponding to an ink flow rate in the individual
flow paths 7. That is, in the case of circulating ink, it is possible to regularly
prepare ink that is not completely flesh but is prevented from being concentrated
or deteriorated to some extent near the ejection ports 2.
[0034] However, if all the liquid delivery mechanisms 12 are driven simultaneously for the
circulation described above, a large current temporarily flows. This creates a need
to secure a sufficient power supply capacity for the liquid delivery mechanism 12
in the liquid ejecting apparatus and may result in an increase in cost. Further, with
the configuration in which the energy generating elements 1 and the liquid delivery
mechanisms 12 are arrayed at high density on the same plane like the present embodiment,
since lines for supplying power to them are also provided densely and intricately,
there is a possibility that drive signals for the energy generating elements 1 include
noise. In consideration of such a situation, in the present embodiment, the liquid
delivery mechanisms 12 arrayed on the same printing element substrate 4 are divided
into a plurality of blocks and are driven per block.
[0035] FIG. 7 is a diagram showing a state where the liquid delivery mechanisms 12 are divided
into blocks. FIG. 7 shows a layout of printing element groups, supply flow paths 8,
and individual flow paths 7 for one color. Printing element arrays are provided on
both sides of each of the two supply flow paths 8 extending in the Y direction, that
is, four printing element arrays are provided in total. FIG. 7 shows the four printing
element arrays as BLKa, BLKb, BLKc, and BLKd.
[0036] In the present embodiment, each individual flow path 7 is equipped with one liquid
delivery mechanism 12. In each printing element array, the liquid delivery mechanisms
12 are divided into blocks each including six consecutive liquid delivery mechanisms
12 and twelve consecutive printing elements. Driving is controlled per block. FIG.
7 shows six liquid delivery mechanisms included in the same block as P1 to P6 (also
referred to as pump 1 to pump 6). The division is made so that the four printing element
arrays BLKa, BLKb, BLKc, and BLKd include the boundaries between adjacent blocks in
different positions in the Y direction. More specifically, the printing element arrays
BLKa and BLKb, to which ink is supplied from the same supply flow path 8, are shifted
from each other in the Y direction by half a cycle (corresponding to three liquid
delivery mechanisms). The printing element arrays BLKc and BLKd are also shifted from
each other in the same manner.
[0037] FIG. 8 is a timing chart of block driving. The liquid delivery operation of performing
driving three times in 100 µsec illustrated in FIG. 5 is performed sequentially for
the liquid delivery mechanisms of P1 to P6 (pump 1 to pump 6). In this example, one-sixth
of the liquid delivery mechanisms 12 provided on the printing element substrate 4
is simultaneously driven, thereby preventing cost from being increased more than necessary
by a large power supply capacity.
[0038] As shown in FIG. 7, the positions of liquid delivery mechanisms 12 that are simultaneously
driven, that is, the positions of liquid delivery mechanisms each of P1, P2, P3, P4,
P5, or P6, are dispersed substantially uniformly on the XY plane of the printing element
substrate 4. In other words, simultaneous driving is performed exclusively for liquid
delivery mechanisms that are uniformly dispersed. Accordingly, noise in a drive signal
for each energy generating element 1 can be sufficiently reduced and a high degree
of driving controllability can be maintained.
[0039] Further, for each liquid delivery mechanism 12, the liquid delivery operation is
repeated intermittently in a period of 600 µsec. Consequently, ink flows constantly
and gently through the entire circulation flow path including the supply flow paths
8 and is replaced with fresh ink not more frequently than necessary in the entire
print head and each ejection port. As a result, the evaporation amount of ink as a
whole is not increased more than necessary and can be reduced to the extent that ink
is not deteriorated, and stable ejection operation can be maintained.
Second Embodiment
[0040] In the present embodiment, the same print head as that of the first embodiment is
used and divisional driving of liquid delivery mechanisms is performed in the same
manner as the first embodiment. In addition, in the present embodiment, the driving
amounts of the liquid delivery mechanisms are adjusted together or separately on various
conditions.
[0041] FIGS. 9A and 9B are diagrams showing a difference in evaporation rate according to
the temperature and humidity of an environment where the printing apparatus is placed.
FIG. 9A shows evaporation rates (evaporation volumes per unit time and unit area)
at the time of opening the ejection ports in association with three stages of each
of the ambient temperature and humidity. FIG. 9A shows that as the temperature increases
and the humidity decreases, the evaporation rate becomes higher.
[0042] FIG. 9B is a graph comparing changes in evaporation rate from the time of opening
the ejection ports in three environments (25°C/50%, 50°C/50%, and 50°C/10%) in the
case of circulating ink in the method of the first embodiment. The evaporation rate
converges to a certain value with time on each condition, but the convergence value
is different depending on the environment where the apparatus is placed. As a result,
the degrees of concentration and deterioration of ink near the ejection ports are
also different depending on the environment where the apparatus is placed.
[0043] In light of the situation described above, in the present embodiment, the driving
amounts of all the liquid delivery mechanisms 12 are adjusted based on combinations
of the ambient temperature and humidity while performing the same divisional driving
as that in the first embodiment. To be more specific, in an environment where the
evaporation rate is relatively high, the liquid delivery mechanisms 12 are driven
three times in one liquid delivery operation as shown in FIG. 5. As the evaporation
rate becomes lower, the number of times of driving of the liquid delivery mechanisms
12 in one liquid delivery operation is reduced or the period of the liquid delivery
operation is doubled (1200 µsec).
[0044] For example, in the case of three environments shown in FIG. 9B, the liquid delivery
mechanisms 12 are driven three times at 50°C/10%, twice at 50°C/50%, and once at 25°C/50%
in one liquid delivery operation, whereby the evaporation rates can be close to each
other.
[0045] The driving control of the liquid delivery mechanisms 12 described above is performed
by the controller 400 for the inkjet print head 100 via the head control unit 404
(see FIG. 3). More specifically, it is only necessary to prestore, in the ROM 402,
a table in which combinations of the ambient temperature and humidity are associated
with the number of times of driving and a driving period of the liquid delivery mechanism
12. The CPU 401 acquires detection values of the temperature and humidity sensors
of the sensor unit 408 and acquires, from the table stored in the ROM 402, the number
of times of driving and driving period of the liquid delivery mechanism 12 corresponding
to the detection values. The liquid delivery mechanisms 12 of the print head 100 can
be driven based on the acquired number of times of driving and driving period.
[0046] In this manner, even if the environment where the printing apparatus is placed is
variously changed, stable ejection operation can be maintained while reducing the
ink evaporation amount of the entire print head to the extent that ink is not deteriorated.
In the above description, the number of times of driving is controlled based on both
the ambient temperature and humidity. However, the advantageous result of avoiding
ink from evaporating more than necessary can be produced even if the control is performed
based on only the ambient temperature or the ambient humidity. Further, the degree
of ink evaporation is affected by the temperature of the printing element substrate
4 as well as the ambient temperature. Thus, a detection value of the diode sensor
provided on the printing element substrate 4 may be acquired in place of or in addition
to the detection value of the ambient temperature sensor so that the number or times
of driving or driving period is controlled based on the acquired value(s).
[0047] Further, the evaporation rate from the ejection ports is affected not only by the
temperature and humidity described above but also by a flow rate of ink flowing through
the common flow paths 8. As the flow rate of ink flowing through the supply flow paths
8 increases, a flow rate in the individual flow paths 7 becomes higher and ink evaporation
from the ejection ports 2 is facilitated. Thus, the number of times of driving and
driving period of the liquid delivery mechanisms 12 may be changed according to the
flow rate in the common flow paths 8 in order to prevent ink from evaporating more
than necessary.
[0048] In this case, the CPU 401 acquires a detection value of a flow rate sensor that detects
the flow rate in the supply flow paths 8 and acquires the number of times of driving
or driving period of the liquid delivery mechanisms 12 corresponding to the detection
value from the table prestored in the ROM 402, in which the flow rate is associated
with the number of times of driving or driving period. The liquid delivery mechanisms
12 of the print head 100 can be driven based on the acquired number of times of driving
or driving period.
[0049] The degree of ink concentration in each ejection port is also affected by an ejection
frequency in the ejection port. Since ink concentration progresses near an ejection
port having a low ejection frequency, it is necessary to circulate ink actively before
the next ejection. In contrast, in an ejection port having a high ejection frequency,
ink is frequently replaced with fresh ink and it is not much necessary to circulate
ink in the individual flow path 7. In a case where one individual flow path 7 includes
two pressure chambers 3 like the present embodiment, even if ink is not ejected from
one ejection port, ink circulation is facilitated to some extent by ejecting ink from
the other ejection port.
[0050] In view of the above, in the present embodiment, based on the ejection frequency
of each printing element, a condition for driving a liquid delivery mechanism 12 included
in an individual flow path 7 including that printing element is adjusted. More specifically,
in an individual flow path 7 including an ejection port of a high ejection frequency,
ink is kept fresh near the ejection port 2 even though a liquid delivery mechanism
12 is not actively driven. Accordingly, the number of times of driving of the liquid
delivery mechanism 12 in one liquid delivery operation is reduced to two or less.
In contrast, in an individual flow path 7 including an ejection port of a low ejection
frequency, although ink concentration and deterioration are predicted, the liquid
delivery mechanism 12 is driven at a suitable timing, for example, before the next
ejection operation, instead of regularly circulating ink. In this manner, stable ejection
operation can be maintained without evaporating ink more than necessary.
[0051] FIG. 10 is a timing chart in the case of performing divisional driving described
in the first embodiment. In FIG. 10, elements 1 and 2, which are energy generating
elements, and a pump 1, which is a liquid delivery mechanism, are provided in the
same individual flow path 7. In the present embodiment, a unit time t allocated to
one ejection operation of the energy generating element 1 is equal to a unit time
t (100 µsec) allocated to one liquid delivery operation of the liquid delivery mechanism
12. The unit time t is divided into two. The first half j1 is allocated to one of
the two energy generating elements 1 included in the individual flow path 7 and the
second half j2 is allocated to the other.
[0052] In two printing elements included in the same individual flow path 7, liquid movement
of ink caused by ejection operation of one printing element is transferred to the
other printing element, which results in meniscus instability. Thus, it is preferable
that the next ejection operation is performed after a time sufficient to stabilize
the liquid movement caused by the ejection operation of the two printing elements.
The time is about 10 to 250 µsec, depending on the dimensions and material of each
element in the printing element substrate 4 and the physical properties of ink. In
the present embodiment, such an interval is set to 100 µsec so that elements 1 and
2 are driven certainly with the interval of 100 µsec or more. Accordingly, in the
present embodiment, the element 2, to which the second half j2 of a unit time is allocated,
is not driven in a unit time after the driving of the element 1, to which the first
half j1 of a unit time is allocated. Further, the element 1 is not driven in a unit
time subsequent to a unit time in which the element 2 is driven. Since the liquid
movement of ink makes meniscus unstable for a certain time during and after the driving
of the liquid delivery mechanism 12, it is preferable that no ejection operation is
performed during that time. In FIG. 10, control is exerted so that ejection operation
is performed with an interval of 100 µsec or more after the driving of the liquid
delivery mechanism 12.
[0053] FIG. 11 and FIG. 12 are timing charts in the case of controlling the number of times
of driving of the liquid delivery mechanism 12 based on the ejection frequencies of
the printing elements. As described above, ink can be replaced with fresh ink in each
ejection port by ejection operation of the ejection port. In other words, since ink
has already been replaced with fresh ink in a pressure chamber 3 immediately after
ejection operation, there is no need for further liquid delivery operation. In a pressure
chamber 3 immediately before ejection operation, since it is clear that ink will be
replaced with fresh ink soon, no liquid delivery operation is necessary unless ink
concentration progressed to affect image quality at that time.
[0054] In light of the situation described above, in an example of FIG. 11, since the element
2 performs ejection operation in a unit time from 100 to 200 µsec, driving of the
pump 1 is cancelled in a subsequent unit time (from 200 to 300 µsec). To be more specific,
the inertia of a flow caused by ejection operation of the element 2 at 150 µsec allows
the element 1 to perform normal ejection operation at 500 µsec, thereby preventing
the occurrence of a problem until the next liquid delivery operation in the pump 1.
Therefore, one liquid delivery operation is cancelled to avoid excessive ink circulation.
[0055] In an example of FIG. 12, since the element 2 performs ejection operation in a unit
time from 300 to 400 µsec, driving of the liquid delivery mechanism 12 is cancelled
in a preceding unit time (from 200 to 300 µsec). To be more specific, the element
2 can perform normal election operation at 350 µsec without liquid delivery operation
in the unit time (from 200 to 300 µsec). Further, the inertia of a flow caused by
the election operation allows the element 1 to perform normal ejection operation at
500 µsec and 600 µsec, thereby preventing the occurrence of a problem until the next
liquid delivery operation in the pump 1. Therefore, one liquid delivery operation
is cancelled to avoid excessive ink circulation. As described above, in a case where
it is clear that the energy generating element 1 in the individual flow path is driven,
the driving amount of the liquid delivery mechanism can be reduced in predetermined
periods before and after the timing of the driving.
[0056] In FIG. 11 and FIG. 12, the number of times of driving of the liquid delivery mechanism
12 is reduced to zero to completely cancel liquid delivery operation per se. However,
the number of times of driving may be reduced from three, the standard number, to
two or less. Alternatively, both the methods of FIG. 11 and FIG. 12 may be used so
that liquid delivery operation is cancelled if ejection operation was performed immediately
before the liquid delivery operation as shown in FIG. 11 and the number of times of
driving is reduced if ejection operation will be performed immediately after the liquid
delivery operation as shown in FIG. 12.
[0057] The control described above can be realized by the CPU 401 referring to a table stored
in the ROM 402 and changing the number of times of driving of the liquid delivery
mechanism 12 based on ejection data temporarily stored in the RAM 403 (see FIG. 3).
More specifically, the CPU 401 closely examines ejection data temporarily stored in
the RAM 403 and, if there is data indicating ejection (1) in a unit time immediately
before or after a unit time in which a liquid delivery mechanism 12 should be driven,
changes the number of times of driving of the liquid delivery mechanism in the unit
time in which the liquid delivery mechanism should be driven. The control may be performed
together with the control based on the ambient temperature and humidity that has been
already described. In this case, the numbers of times of driving of all the liquid
delivery mechanisms 12 are controlled uniformly based on the ambient temperature and
humidity and then controlled separately based on ejection data about each printing
element.
[0058] As described above, according to the present embodiment, driving of a plurality of
liquid delivery mechanisms 12 can be separately controlled based on an ejection frequency
in each printing element in addition to the environment where the liquid ejecting
apparatus is placed. As a result, besides the advantageous result explained in the
first embodiment, it is possible to produce an advantageous result of maintaining
stable ejection operation even if the environment is variously changed or the ejection
ports 2 have various ejection frequencies according to image data.
Third Embodiment
[0059] FIGS. 13A and 13B are diagrams showing a flow path configuration of a printing element
substrate 4 adopted in the present embodiment. FIG. 13A is a perspective view of the
printing element substrate 4 from the side of ejection ports (+Z side) and FIG. 13B
is a cross-sectional view taken along line XIIIB-XIIIB. Differences between the printing
element substrate of the present embodiment and that of the embodiments described
above with reference to FIGS. 4A and 4B will be described below.
[0060] In the printing element substrate 4 of the present embodiment, collection flow paths
8' through which ink flows in a -Y direction are provided on both sides of a supply
flow path 8 through which ink flows in the +Y direction. The supply flow path 8 is
connected to the two collection flow paths 8' by a plurality of individual flow paths
7 extending in the X direction. Each individual flow path 7 has one printing element
including an energy generating element 1, an ejection port 2, and a pressure chamber
3. In each individual flow path 7, a liquid delivery mechanism 12 is provided in a
connection flow path 6 closer to the supply flow path 8 than the energy generating
element 1.
[0061] In the present embodiment, since each individual flow path 7 includes only one printing
element, liquid movement caused by ejection operation of an adjacent printing element
is less than that in the embodiments described above. Therefore, drive timings for
ejection can be set with a high degree of freedom without taking the effect of liquid
movement into consideration.
[0062] The supply flow path 8 is connected to a first pressure room (not shown) having a
pressure Ph and the collection flow paths 8' are connected to a second pressure room
(not shown) having a pressure Pl lower than Ph. Consequently, ink gently flows from
the supply flow path 8 to the collection flow paths 8' through the individual flow
paths 7 connecting the supply flow path 8 to the collection flow paths 8' regardless
of the presence or absence of the liquid delivery mechanism 12. As described above,
in the present embodiment in which ink regularly flows through the individual flow
paths 7, ink concentration in the pressure chambers 3 can be further suppressed and
the number of times of driving of the liquid delivery mechanisms 12 can be further
reduced as compared with the embodiments described above.
[0063] Further, the liquid delivery mechanism 12 is provided in the connection flow path
6 connecting the supply flow path 8 to the pressure chamber 3 and the flow path resistance
of the connection flow path 6 is less than that of the connection flow path 6' connecting
the collection flow paths 8' to the pressure chamber. Accordingly, the ink flow from
the supply flow path 8 to the collection flow paths 8' can be further facilitated
by driving the liquid delivery mechanisms 12. Although various liquid delivery mechanisms
can be used as the liquid delivery mechanism 12 like the embodiments described above,
a case of using a piezoelectric actuator will be described below.
[0064] Specific examples of the dimensions of the above structure are explained below. The
size of the energy generating element 1 is 20 µm × 25 µm, the diameter of the ejection
port 2 is 20 µm, and the area of the pressure chamber 3 is 25 µm × 30 µm. The width
of the connection flow paths 6 and 6' is 25 µm. The length of the upstream connection
flow path 6 is 40 µm and the length of the downstream connection flow path 6' is 20
µm. The height of the whole of the individual flow path 7 is 15 µm. The width of the
supply flow path 8 and collection flow path 8' is 40 µm, the thickness of the ejection
port forming member 11 is 12 µm, and a pressure difference Ph-Pl between the pressure
Ph created by the first pressure room connected to the supply flow path 8 and the
pressure Pl created by the second pressure room connected to the collection flow path
8' is 0 to 100 mmAq. The viscosity of ink to be used is 3 cP and the amount of ink
ejection from each ejection port is 7 pl. It is preferable that the pressure difference
Ph-Pl is properly adjusted based on the temperature and humidity of a use environment,
that is, an ink evaporation rate.
[0065] In each of the printing element arrays located on both sides of the supply flow path
8, a plurality of printing elements are arrayed in the Y direction at a density of
600 dpi. The two printing element arrays are shifted from each other by half the pitch
in the Y direction. In the present embodiment, a plurality of printing element substrates
4 each having the array shown in FIG. 13A are arranged in the Y direction to form
a full line type print head 100 capable of printing an image on an A4 print medium
at a resolution of 1200 dpi.
[0066] In the present embodiment, five liquid delivery mechanisms 12 adjacent to each other
in the Y direction (that is, five consecutive printing elements) are regarded as one
block. The printing elements and liquid delivery mechanisms 12 are divided into a
plurality of blocks and controlled. At this time, the boundaries between adjacent
blocks in one printing element array are shifted from those in the other by half the
pitch. The five liquid delivery mechanisms 12 are driven in the order of P1 (pump
1), P2 (pump 2), P3 (pump 3), P4 (pump 4), and P5 (pump 5) like the embodiments described
above.
[0067] FIG. 14 is an example of a timing chart of block driving in the present embodiment.
FIG. 14 shows drive pulses applied to five energy generating elements (element 1 to
element 5) included in the same block and driving states of five liquid delivery mechanisms
(pump 1 to pump 5). Also in the present embodiment, liquid delivery operation of driving
a liquid delivery mechanism three times in 100 µsec illustrated in FIG. 5 is basically
performed for the pump 1 to pump 5 (PI to P5) in sequence. In addition, in the present
embodiment, driving of the liquid delivery mechanisms 12 is further controlled for
each individual flow path 7.
[0068] Also in the present embodiment, driving of the liquid delivery mechanisms 12 is adjusted
based on ejection data before and after unit times t allocated to respective liquid
delivery mechanisms 12 like the second embodiment described with reference to FIG.
11 and FIG. 12. Detailed description will be provided below with reference to FIG.
14.
[0069] In FIG. 14, an element 1 (energy generating element) and a pump 1 (liquid delivery
mechanism) are provided in the same individual flow path 7, and the same goes for
an element 2 and a pump 2, an element 3 and a pump 3, an element 4 and a pump 4, and
an element 5 and a pump 5. In a case where each pump is driven, an element provided
in an individual flow path 7 including the pump is not driven. For example, the element
1 is not driven in a unit time t1 in which the pump 1 is driven. In a case where ejection
data exists in that pixel position (that timing of that element), ejection operation
is performed by another printing element capable of printing in the same pixel position.
In addition, the number of times of driving of each pump is changed based on ejection
data before and after a unit time in which the pump is driven.
[0070] For example, regarding a unit time t2 from 600 to 700 µsec in which the pump 2 is
driven, the element 2 performs ejection operation in both of a unit time t1 immediately
before the unit time t2 and a unit time t3 immediately after the unit time t2 and
it is possible to predict that a pressure chamber 3 stores flesh ink. Thus, the number
of times of driving is changed from three, the normal number, to one to avoid excessive
ink circulation.
[0071] Regarding a unit time t5 from 400 to 500 µsec in which the pump 5 is driven, the
element 5 performs ejection operation in a unit time t1 immediately after the unit
time t5 but no ejection operation is performed for some time including a unit time
t4 immediately before the unit time t5. Since there is a possibility of ink concentration
in the pressure chamber 3, driving is performed three times as usual to replace ink
with fresh ink.
[0072] Regarding the unit time t4 from 300 to 400 µsec in which the pump 4 is driven, no
ejection operation is performed by the element 4 for some time including the unit
time t3 immediately before the unit time t4 and it is therefore conceivable that ink
in the pressure chamber 3 is concentrated to some extent. On the other hand, no ejection
operation is performed by the element 4 for some time including the unit time t5 immediately
after the unit time t4. Thus, there is no possibility of image deterioration caused
by ejection of concentrated ink. Accordingly, it is determined that there is little
need to supply flesh ink to the pressure chamber at this timing and the driving of
the pump 4 is cancelled to avoid excessive ink circulation. It should be noted that,
in the next unit time t4 from 800 to 900 µsec, driving is performed twice intermittently
to prevent the liquid delivery function of the pump from being impaired by excessive
ink concentration.
[0073] As described above, in a case where each individual flow path 7 includes one liquid
delivery mechanism 12 and one printing element, driving of the liquid delivery mechanisms
12 can be adjusted separately and closely based on ejection data about the corresponding
printing elements 1 to 5.
[0074] FIG. 15 is another example of the timing chart of block driving in the present embodiment.
FIG. 15 is different from FIG. 14 in that preliminary ejection operation is used as
a method for replacing concentrated ink with flesh ink in addition to the liquid delivery
operation. In FIG. 15, drive pulses to be applied to elements 1 to 5 for the preliminary
ejection operation are shown by broken lines.
[0075] The preliminary ejection operation means ejection operation that is preliminary and
is irrelevant to ejection data based on image data. In a state where no ejection data
exists for a while and ink concentration progresses, the ejection state of a printing
element can be stabilized by performing the preliminary ejection operation at a proper
timing. Further, since deteriorated ink is discharged from the circulation flow path,
the preliminary ejection operation is also preferable for stabilization of the degree
of concentration in the entire circulation flow path.
[0076] Since the preliminary ejection operation only requires that concentrated ink be discharged,
there is no need to ensure the same ejection quality as that in ejection operation
based on image data. The preliminary ejection operation in the present embodiment
is therefore performed in the same unit time as the liquid delivery operation. However,
in a full line type inkjet printing apparatus like the present embodiment, the preliminary
ejection operation in printing operation is performed for an image on a print medium.
Accordingly, it is preferable that the preliminarily ejection is performed on a condition
that, for example, an area has a high density, so that deterioration in image quality
is not recognized even if a dot irrelevant to the image is printed. Detailed description
will be provided below with reference to FIG. 15.
[0077] Regarding the element 1, ejection data based on image data does not exist from 220
to 650 µsec and ink concentration is predicted. Thus, the pump 1 is driven once and
preliminary ejection is performed once in a unit time t1 immediately before ejection
at 650 µsec.
[0078] Regarding the element 2, ejection data based on image data does not exist from 0
to 250 µsec and ink concentration is predicted. Thus, the pump 2 is driven twice and
preliminary ejection is performed once in a unit time t2 immediately before ejection
at 250 µsec.
[0079] Regarding the element 3, ejection data based on image data appears relatively frequently
and the possibility of ink concentration is low. Thus, liquid delivery operation is
cancelled and preliminary ejection is performed once in a unit time t3.
[0080] Regarding the element 4, although ejection data based on image data is few and ink
concentration is predicted, concentrated ink is not ejected based on image data either.
Thus, liquid delivery operation is cancelled and no preliminary ejection is performed
in a unit time t4.
[0081] Regarding the element 5, ejection data based on image data does not exist from 0
to 550 µsec and ink concentration is predicted. Thus, the pump 5 is driven twice and
preliminary ejection is performed once in a unit time t5 immediately before ejection
at 550 µsec.
[0082] As described above, concentration of circulating ink can be reduced as a whole while
maintaining a stable ejection state in each printing element by the use of the preliminary
ejection operation as a method for replacing concentrated ink with flesh ink in addition
to the liquid delivery operation.
Fourth Embodiment
[0083] FIGS. 16A and 16B are diagrams showing a flow path configuration of a printing element
substrate 4 adopted in the present embodiment. FIG. 16A is a perspective view of the
printing element substrate 4 from the side of ejection ports (+Z side) and FIG. 16B
is a cross-sectional view taken along line XVIB-XVIB.
[0084] As shown in FIG. 16B, a supply flow path 8 of the present embodiment is formed as
an opening penetrating a silicon substrate 4a and is connected to an individual flow
path via an inlet 13 and an outlet 13' that are formed in a functional layer 9. As
shown in FIG. 16A, a plurality of individual flow paths 7 are formed in parallel in
a direction inclined with respect to the Y direction. In each individual flow path
7, four printing elements and five liquid delivery mechanisms 12 are alternately arranged
in a line.
[0085] The inlet 13 and the outlet 13' are provided on respective ends of each individual
flow path 7. An ink flow shown by arrows in FIG. 16B is created by a difference in
flow path resistance between the inlet and outlet and driving of five liquid delivery
mechanisms 12. More specifically, ink flows from the supply flow path 8 through the
inlet 13, passes through four pressure chambers 3, and then flows into the supply
flow path 8 through the outlet 13'. Although various configurations can be used for
the liquid delivery mechanism 12 in the present embodiment, an alternating current
electro-osmotic (ACEO) pump is adopted in the present embodiment.
[0086] FIG. 17 is a plan view of the ACEO pump. Two groups of comb-like electrodes have
different widths and heights and are interdigitally arranged. An AC voltage is applied
between the electrodes, thereby producing an asymmetric electric field in liquid located
above the electrodes and causing the liquid to flow in a desired direction. The ACEO
pump is suitable for a case where an individual flow path 7 has a relatively long
length and extends in one direction like the present embodiment.
[0087] Specific examples of the dimensions of the above structure are explained below. The
size of the energy generating element 1 is 18 µm × 22 µm, the diameter of the ejection
port 2 is 18 µm, and the area of the pressure chamber 3 is 25 µm × 30 µm. A communication
flow path 5 interposed between the pressure chambers 3 has a width of 18 µm and a
length of 7 µm. The opening area of the inlet 13 is 10 µm × 15 µm, the opening area
of the outlet 13' is 5 µm × 15 µm, and the height of the whole of the individual flow
path 7 is 12 µm. The width of the supply flow path 8 is 250 µm and the thickness of
the ejection port forming member 11 is 10 µm. The viscosity of ink to be used is 3
cP and the amount of ink ejection from each ejection port is 4 pl.
[0088] In the present embodiment, five consecutive liquid delivery mechanisms 12 and four
energy generating elements 1 included in each individual flow path 7 are regarded
as one block and block driving is performed in the same manner as the embodiments
described above. At this time, five liquid delivery mechanisms 12 included in the
same individual flow path 7 may be sequentially driven from P1, but a plurality of
liquid delivery mechanisms 12 may be driven at the same timing. For example, P2 and
P4 may be driven together after driving P1, P3, and P5 together.
[0089] Also in the present embodiment described above, stable ejection operation can be
maintained while reducing the ink evaporation amount as a whole to avoid ink deterioration
as well as reducing the power supply capacity and the possibility of noise, like the
embodiments described above.
Modified Examples
[0090] The structures and control methods of the printing element substrate described in
the above embodiments can be modified, combined with each other, and replaced with
each other. For example, the individual flow path 7 shown in FIG. 4A may include more
printing elements and liquid delivery mechanisms 12. In this case, the liquid delivery
mechanisms 12 may have different strengths and frequencies of driving according to
their positions in the individual flow path. However, as the number of pressure chambers
3 or liquid delivery mechanisms included in one individual flow path 7 increases,
the individual flow path 7 itself becomes larger. In consideration of the effect of
ejection operation in an upstream printing element on ejection operation in a downstream
printing element, the number of pressure chambers provided in one individual flow
path 7 may be about 10 at most and preferably be five or less.
[0091] Further, pumps in the same block should not necessarily be driven in the order of
P1 to P6 as shown in FIG. 7 and may be driven in the order of P6 to P1 or other orders.
Furthermore, although the standard number of times of driving of liquid delivery mechanisms
in one liquid delivery operation is three in the above description, it may be variously
adjusted and may be two or less or four or more.
[0092] The first and second embodiments show the configuration in which a plurality of individual
flow paths are allocated to one block and the fourth embodiment shows the configuration
in which one individual flow path is allocated to one block. However, the present
invention may be modified to include a plurality of blocks in one individual flow
path. For example, this corresponds to the case of driving P1, P3, and P5 together
and then driving P2 and P4 together in the configuration shown in FIG. 16A.
[0093] In the description of the third embodiment with reference to FIG. 15, the preliminary
ejection operation is performed to discharge concentrated ink near the ejection ports.
However, this may be replaced with or combined with an aspect of applying energy to
the energy generating element 1 below a level at which ejection operation is performed.
In this case, although concentrated ink is not discharged, the meniscus in the ejection
ports is vibrated, thereby stirring concentrated ink inside the pressure chambers.
[0094] Further, in the above embodiments, a pressure difference produced by an unshown pump
is used to control fluid pressures in the supply flow path 8 and collection flow path
8'. However, the present invention is not limited to this. For example, an ink flow
may be produced by the use of capillary action or a difference in hydraulic head between
upstream and downstream ink tanks.
[0095] Further, the full line type print head having printing element substrates 4 arrayed
by a distance corresponding to the width of a print medium has been described as an
example with reference to FIG. 1. However, the flow path configurations of the present
invention may also be applied to a serial type print head. It should be noted that
an elongated print head such as a full line type print head can attain the advantageous
result of the present invention more conspicuously because the problem to be solved
by the present invention, that is, ink evaporation and deterioration, occurs more
frequently in such a print head.
[0096] While the present invention has been described with reference to exemplary embodiments,
it is to be understood that the invention is not limited to the disclosed exemplary
embodiments. The scope of the invention is defined by the following claims.
1. An ink ejecting apparatus comprising:
a plurality of individual flow paths (7) each having
a pressure chamber (3) configured to store ink;
an energy generating element (1) which is provided in a position corresponding to
the pressure chamber (3) and which is configured to provide energy to ink in the pressure
chamber (3); and
an ejection port (2) which is provided in a position corresponding to the energy generating
element (1) and from which ink provided with energy by the energy generating element
(1) is ejected;
wherein the ink ejecting apparatus is characterized in that
each of the plurality of individual flow paths (7) has a liquid delivery mechanism
(12) located upstream of the pressure chamber (3) which is prepared in association
with the pressure chamber (3) and which is configured to facilitate a flow of ink
through the pressure chamber (3); and
the ink ejecting apparatus further comprises
a control unit (400) configured to control driving of the plurality of the liquid
delivery mechanisms (12),
wherein the control unit (400) is configured to divide the plurality of the liquid
delivery mechanisms (12) into a plurality of blocks and to drive the liquid delivery
mechanisms (12), which are included in each of the blocks, at different timings.
2. The ink ejecting apparatus according to claim 1, wherein the plurality of the liquid
delivery mechanisms (12) are arrayed on the same plane as a plurality of the energy
generating elements (1), and the liquid delivery mechanisms (12) that are simultaneously
driven by the control unit (400) are dispersed uniformly on the plane.
3. The ink ejecting apparatus according to claim 1 or 2, wherein in a case where a flow
rate detected by a flow rate sensor in a flow path (8) which is common to the plurality
of the pressure chambers (3) and for supplying ink to the plurality of the pressure
chambers (3) increases, the control unit (400) is configured to reduce the driving
amounts of the plurality of the liquid delivery mechanisms (12).
4. The ink ejecting apparatus according to any one of claims 1 to 3, wherein the control
unit (400) is configured to change the driving amounts of the plurality of the liquid
delivery mechanisms (12) based on at least one of an ambient temperature and an ambient
humidity.
5. The ink ejecting apparatus according to any one of claims 1 to 4, wherein the control
unit (400) is configured to change the driving amounts of the plurality of the liquid
delivery mechanisms (12) based on a temperature of a substrate (4) on which a plurality
of the energy generating elements (1) are provided.
6. The ink ejecting apparatus according to any one of claims 1 to 5, wherein based on
ejection data for driving the energy generating element (1), the control unit is configured
to change the driving amount of the liquid delivery mechanism (12) corresponding to
the energy generating element (1) individually.
7. The ink ejecting apparatus according to claim 6, wherein for a predetermined period
before or after the energy generating element (1) is driven, the control unit (400)
is configured to reduce the driving amount of the liquid delivery mechanism (12) corresponding
to the energy generating element (1).
8. The ink ejecting apparatus according to claim 6 or 7, wherein the control unit is
configured to generate new ejection data for driving the energy generating element
(12) based on the ejection data for driving the energy generating element (1) to eject
ink from the ejection port and to reduce the driving amount of the liquid delivery
mechanism (12) corresponding to the energy generating element (1).
9. The ink ejecting apparatus according to any one of claims 1 to 8, wherein the control
unit (400) is configured to change the driving amount of the liquid delivery mechanism
(12) by adjusting at least one of the number of times of driving and a driving period
of the liquid delivery mechanism (12) in a unit time.
10. The ink ejecting apparatus according to any one of claims 1 to 9, wherein the liquid
delivery mechanism (12) and the pressure chambers (3) associated with the liquid delivery
mechanism (12) are arranged in a line in a direction of a flow of ink in the same
flow path.
11. The ink ejecting apparatus according to any one of claims 1 to 9, wherein one liquid
delivery mechanism (12) is prepared for each of the pressure chambers (3).
12. A control method of an ink ejecting apparatus, the ink ejecting apparatus comprising:
a plurality of individual flow paths (7) each having
a pressure chamber (3) which stores ink;
an energy generating element (1) which is provided in a position corresponding to
the pressure chamber (3) and provides energy to ink in the pressure chamber (3);
an ejection port (2) which is provided in a position corresponding to the energy generating
element (1) and from which ink provided with energy by the energy generating element
(1) is ejected; and wherein the method is characterized in that
a liquid delivery mechanism (12) is located upstream of the pressure chamber (3) which
is prepared in association with the pressure chamber (3) and facilitates a flow of
ink through the pressure chamber (3),
and in that the plurality of the liquid delivery mechanisms (12) is divided into a plurality
of blocks and the liquid delivery mechanisms (12) included in each of the blocks are
driven at different timings.
1. Tintenausstoßvorrichtung mit:
einer Vielzahl einzelner Strömungspfade (7), wobei jeder Folgendes hat:
eine Druckkammer (3), die eingerichtet ist, um Tinte zu speichern;
ein Energieerzeugungselement (1), das an einer Position vorgesehen ist, die der Druckkammer
(3) entspricht, und das eingerichtet ist, um Tinte in der Druckkammer (3) mit Energie
zu versehen; und
eine Ausstoßöffnung (2), die an einer Position vorgesehen ist, die dem Energieerzeugungselement
(1) entspricht, und aus der Tinte, die durch das Energieerzeugungselement (1) mit
Energie versehen wird, ausgestoßen wird;
wobei die Tintenausstoßvorrichtung dadurch gekennzeichnet ist, dass
jeder von der Vielzahl von einzelnen Strömungspfaden (7) einen Flüssigkeitszufuhrmechanismus
(12) hat, der stromaufwärts von der Druckkammer (3) gelegen ist, der zusammen mit
der Druckkammer (3) angefertigt wird und der eingerichtet ist, um eine Tintenströmung
durch die Druckkammer (3) zu erleichtern; und
die Tintenausstoßvorrichtung des Weiteren Folgendes aufweist:
eine Steuerungseinheit (400), die eingerichtet ist, um einen Antrieb der Vielzahl
von den Flüssigkeitszufuhrmechanismen (12) zu steuern,
wobei die Steuerungseinheit (400) eingerichtet ist, um die Vielzahl von den Flüssigkeitszufuhrmechanismen
(12) in eine Vielzahl von Blöcken aufzuteilen und die Flüssigkeitszufuhrmechanismen
(12), die in jedem der Blöcke umfasst sind, zu verschiedenen Zeitabstimmungen anzutreiben.
2. Tintenausstoßvorrichtung gemäß Anspruch 1, wobei die Vielzahl von den Flüssigkeitszufuhrmechanismen
(12) an derselben Ebene wie eine Vielzahl von den Energieerzeugungselementen (1) angeordnet
sind und die Flüssigkeitszufuhrmechanismen (12), die durch die Steuerungseinheit (400)
gleichzeitig betrieben werden, an der Ebene gleichmäßig verteilt sind.
3. Tintenausstoßvorrichtung gemäß Anspruch 1 oder 2, wobei in einem Fall, bei dem eine
Strömungsrate, die durch einen Strömungsratensensor in einem Strömungspfad (8) erfasst
wird, den die Vielzahl der Druckkammern (3) gemeinsam haben und der zum Zuführen von
Tinte zu der Vielzahl der Druckkammern (3) dient, ansteigt, die Steuerungseinheit
(400) eingerichtet ist, die Antriebsbeträge der Vielzahl von den Flüssigkeitszufuhrmechanismen
(12) zu reduzieren.
4. Tintenausstoßvorrichtung gemäß einem der Ansprüche 1 bis 3, wobei die Steuerungseinheit
(400) eingerichtet ist, um die Antriebsbeträge der Vielzahl von den Flüssigkeitszufuhrmechanismen
(12) beruhend auf einer Umgebungstemperatur und/oder einer Umgebungsfeuchtigkeit zu
ändern.
5. Tintenausstoßvorrichtung gemäß einem der Ansprüche 1 bis 4, wobei die Steuerungseinheit
(400) eingerichtet ist, um die Antriebsbeträge der Vielzahl von den Flüssigkeitszufuhrmechanismen
(12) beruhend auf einer Temperatur eines Substrats (4) zu ändern, auf dem eine Vielzahl
von den Energieerzeugungselementen (1) vorgesehen sind.
6. Tintenausstoßvorrichtung gemäß einem der Ansprüche 1 bis 5, wobei, beruhend auf Ausstoßdaten
zum Antreiben des Energieerzeugungselements (1), die Steuerungseinheit eingerichtet
ist, den Antriebsbetrag des Flüssigkeitszufuhrmechanismus (12), der dem Energieerzeugungselement
(1) entspricht, einzeln zu ändern.
7. Tintenausstoßvorrichtung gemäß Anspruch 6, wobei für eine vorbestimmte Zeitspanne
bevor oder nachdem das Energieerzeugungselement (1) angetrieben wird die Steuerungseinheit
(400) eingerichtet ist, den Antriebsbetrag des Flüssigkeitszufuhrmechanismus (12),
der dem Energieerzeugungselement (1) entspricht, zu reduzieren.
8. Tintenausstoßvorrichtung gemäß Anspruch 6 oder 7, wobei die Steuerungseinheit eingerichtet
ist, um neue Ausstoßdaten zum Antreiben des Energieerzeugungselements (12) beruhend
auf den Ausstoßdaten zum Antreiben des Energieerzeugungselements (1) zu erzeugen,
um Tinte aus der Ausstoßöffnung auszustoßen, und den Antriebsbetrag des Flüssigkeitszufuhrmechanismus
(12), der dem Energieerzeugungselement (1) entspricht, zu reduzieren.
9. Tintenausstoßvorrichtung gemäß einem der Ansprüche 1 bis 8, wobei die Steuerungseinheit
(400) eingerichtet ist, um den Antriebsbetrag des Flüssigkeitszufuhrmechanismus (12)
durch ein Einstellen der Anzahl von Malen eines Antreibens und/oder einer Antriebszeitspanne
des Flüssigkeitszufuhrmechanismus (12) in einer Zeiteinheit zu ändern.
10. Tintenausstoßvorrichtung gemäß einem der Ansprüche 1 bis 9, wobei der Flüssigkeitszufuhrmechanismus
(12) und die Druckkammer (3), die dem Flüssigkeitszufuhrmechanismus (12) angegliedert
ist, in einer Richtung einer Strömung in dem gleichen Strömungspfad in einer Reihe
angeordnet sind.
11. Tintenausstoßvorrichtung gemäß einem der Ansprüche 1 bis 9, wobei ein Flüssigkeitszufuhrmechanismus
(12) für jede von den Druckkammern (3) angefertigt ist.
12. Steuerungsverfahren einer Tintenausstoßvorrichtung, wobei die Tintenausstoßvorrichtung
Folgendes aufweist:
eine Vielzahl einzelner Strömungspfade (7), wobei jeder Folgendes hat:
eine Druckkammer (3), die Tinte speichert;
ein Energieerzeugungselement (1), das an einer Position vorgesehen ist, die der Druckkammer
(3) entspricht, und Tinte in der Druckkammer (3) mit Energie versieht;
eine Ausstoßöffnung (2), die an einer Position vorgesehen ist, die dem Energieerzeugungselement
(1) entspricht, und aus der Tinte, die durch das Energieerzeugungselement (1) mit
Energie versehen wird, ausgestoßen wird; und wobei das Verfahren dadurch gekennzeichnet ist, dass
ein Flüssigkeitszufuhrmechanismus stromaufwärts der Druckkammer (3) gelegen ist, der
zusammen mit der Druckkammer (3) angefertigt wird und eine Tintenströmung durch die
Druckkammer (3) erleichtert, und dass
die Vielzahl von den Flüssigkeitszufuhrmechanismen (12) in eine Vielzahl von Blöcken
aufgeteilt wird und die Flüssigkeitszufuhrmechanismen (12), die in jedem der Blöcke
umfasst sind, zu verschiedenen Zeitabstimmungen angetrieben werden.
1. Appareil d'éjection d'encre, comprenant :
une pluralité de trajets d'écoulement individuels (7) comportant individuellement
une chambre de pression (3) configurée pour contenir de l'encre ;
un élément de génération d'énergie (1) qui est disposé à une position correspondant
à la chambre de pression (3) et qui est configuré pour appliquer de l'énergie à l'encre
se trouvant dans la chambre de pression (3) ; et
un orifice d'éjection (2) qui est disposé à une position correspondant à l'élément
de génération d'énergie (1) et à partir duquel est éjectée une encre à laquelle de
l'énergie est appliquée par l'élément de génération d'énergie (1) ;
où l'appareil d'éjection d'encre est caractérisé en ce que
chacun de la pluralité de trajets d'écoulement individuels (7) comporte un mécanisme
de distribution de liquide (12) situé en amont de la chambre de pression (3), qui
est préparé en association avec la chambre de pression (3) et qui est configuré pour
faciliter un écoulement d'encre à travers la chambre de pression (3) ; et
l'appareil d'éjection d'encre comprenant en outre
une unité de commande (400) configurée pour commander une attaque de la pluralité
des mécanismes de distribution de liquide (12),
dans lequel l'unité de commande (400) est configurée pour diviser la pluralité des
mécanismes de distribution de liquide (12) en une pluralité de blocs et pour attaquer
les mécanismes de distribution de liquide (12), qui sont compris dans chacun des blocs,
à des instants différents.
2. Appareil d'éjection d'encre selon la revendication 1, dans lequel la pluralité des
mécanismes de distribution de liquide (12) forment un réseau sur le même plan qu'une
pluralité des éléments de génération d'énergie (1), et les mécanismes de distribution
de liquide (12) qui sont attaqués simultanément par l'unité de commande (400) sont
dispersés uniformément sur le plan.
3. Appareil d'éjection d'encre selon la revendication 1 ou 2, dans lequel, dans un cas
d'augmentation d'un débit détecté par un capteur de débit dans un trajet d'écoulement
(8) qui est commun à la pluralité des chambres de pression (3) et destiné à alimenter
en encre la pluralité des chambres de pression (3), l'unité de commande (400) est
configurée pour réduire les valeurs d'attaque de la pluralité des mécanismes de distribution
de liquide (12).
4. Appareil d'éjection d'encre selon l'une quelconque des revendications 1 à 3, dans
lequel l'unité de commande (400) est configurée pour modifier les valeurs d'attaque
de la pluralité des mécanismes de distribution de liquide (12) sur la base d'au moins
l'une d'une température ambiante et d'une humidité ambiante.
5. Appareil d'éjection d'encre selon l'une quelconque des revendications 1 à 4, dans
lequel l'unité de commande (400) est configurée pour modifier les valeurs d'attaque
de la pluralité des mécanismes de distribution de liquide (12) sur la base d'une température
d'un substrat (4) sur lequel sont disposés une pluralité des éléments de génération
d'énergie (1).
6. Appareil d'éjection d'encre selon l'une quelconque des revendications 1 à 5, dans
lequel, sur la base de données d'éjection servant à attaquer l'élément de génération
d'énergie (1), l'unité de commande est configurée pour modifier la valeur d'attaque
du mécanisme de distribution de liquide (12) correspondant individuellement à l'élément
de génération d'énergie (1).
7. Appareil d'éjection d'encre selon la revendication 6, dans lequel, pendant une période
prédéterminée qui précède ou qui suit une attaque de l'élément de génération d'énergie
(1), l'unité de commande (400) est configurée pour réduire la valeur d'attaque du
mécanisme de distribution de liquide (12) correspondant à l'élément de génération
d'énergie (1).
8. Appareil d'éjection d'encre selon la revendication 6 ou 7, dans lequel l'unité de
commande est configurée pour générer de nouvelles données d'éjection pour attaquer
l'élément de génération d'énergie (12) sur la base des données d'éjection d'attaque
de l'élément de génération d'énergie (1) pour éjecter de l'encre à partir de l'orifice
d'éjection et pour réduire la valeur d'attaque du mécanisme de distribution de liquide
(12) correspondant à l'élément de génération d'énergie (1).
9. Appareil d'éjection d'encre selon l'une quelconque des revendications 1 à 8, dans
lequel l'unité de commande (400) est configurée pour modifier la valeur d'attaque
du mécanisme de distribution de liquide (12) par un réglage d'au moins l'un du nombre
d'attaques et d'une période d'attaque du mécanisme de distribution de liquide (12)
par unité de temps.
10. Appareil d'éjection d'encre selon l'une quelconque des revendications 1 à 9, dans
lequel le mécanisme de distribution de liquide (12) et les chambres de pression (3)
associées au mécanisme de distribution de liquide (12) sont disposés sur une ligne
dans un sens d'écoulement d'encre dans le même trajet d'écoulement.
11. Appareil d'éjection d'encre selon l'une quelconque des revendications 1 à 9, dans
lequel un mécanisme de distribution de liquide (12) est préparé pour chacune des chambres
de pression (3).
12. Procédé de commande d'un appareil d'éjection d'encre, l'appareil d'éjection d'encre
comprenant :
une pluralité de trajets d'écoulement individuels (7) comportant individuellement
une chambre de pression (3) qui contient de l'encre ;
un élément de génération d'énergie (1) qui est disposé à une position correspondant
à la chambre de pression (3) et applique de l'énergie à de l'encre se trouvant dans
la chambre de pression (3) ;
un orifice d'éjection (2) qui est disposé à une position correspondant à l'élément
de génération d'énergie (1) et à partir duquel est éjectée une encre à laquelle de
l'énergie est appliquée par l'élément de génération d'énergie (1) ; et où le procédé
est caractérisé
en ce qu'un mécanisme de distribution de liquide (12) est situé en amont de la chambre de pression
(3), qui est préparé en association avec la chambre de pression (3) et facilite un
écoulement d'encre à travers la chambre de pression (3), et
en ce que la pluralité des mécanismes de distribution de liquide (12) sont divisés en une pluralité
de blocs et les mécanismes de distribution de liquide (12) compris dans chacun des
blocs sont attaqués à des instants différents.